This invention relates to an improved air conditioning system and more particularly to a system utilizing a novel air thermodynamic cycle and performing apparatus providing for simultaneous and efficient removal of the sensible and latent heats from the air to be conditioned.
Heretofore, the standard thermodynamic cycle of an air conditioning system utilized the vapor compression cycle which conditioned the room return air to a predetermined cooler temperature and a less humid state prior to injection back into the room/space. This cycle included a first step in which the return air underwent a sensible cooling operation beyond the desired lower temperature to the dew point temperature of the air. This extended sensible cooling step was followed by condensation of the sensibly cooled air so as to provide for removal of the latent heat therein, and thus arrive at the desired lower humid state. The air is then reheated to arrive at the desired temperature state before injection into the room/space--this step being an optional one. This system requires an excessive cooling/sensible heat removal of the processed air to a temperature lower than that of the desired temperature parameter. This extra cooling requires a lower evaporating temperature of the refrigerant in the evaporator apparatus resulting in a lower coefficient of performance of the system.
A desiccant cycle has also been employed in an air conditioning system. This cycle included a first step in which the moisture of the return air is removed by interaction with a desiccant material, such moisture removal resulting in an increase in the air temperature. This dehumidification is followed by a cooling step in which the dried air is sensibly cooled by a heat exchange with the ambient air saturated with water. Once cooled, an adiabatic humidification step is provided by adding moisture to the air which also cools the processed air whereby to condition the room air to the desired temperature and humidity parameters prior to injection back into the room/space. In this process, an excessive moisture removal/latent heat removal from the air is required beyond the desired humidity parameter so that the sensible cooling step can be performed without the use of a refrigerant. This excessive drying step, however, requires excessive thermal energy for regenerating the desiccant. Thus, the operating efficiency of the common desiccant cycle is low.
Thus, it is appreciated that in both of the known air conditioning systems respectively utilizing the vapor compression and desiccant cycles energy is not efficiently utilized to arrive at the desired state of the conditioned air which is to be injected into the living area.
Accordingly, addressing this waste of energy, I have invented an air conditioning system and performing apparatus utilizing a new air thermodynamic cycle which simultaneously cools the return air to the extent required to only cover the desired sensible heat loss while drying this air to the extent required only to cover the latent heat loss corresponding to the desired removal of moisture therefrom. Thus, an air thermodynamic cycle presenting a simutaneous and direct cooling and dehumidification of the air is provided without waste of energy therein.
The performing apparatus includes first and second heat exchangers having a heat exchange surface of interaction such as projecting fins with the fins further having a desiccant material thereon. The first and second heat exchangers are switchable between condenser and evaporator modes as provided by controlled routing of the refrigerant and the room return and outside ambient air. In the evaporator mode one heat exchanger simultaneously cools and dries the return air. The other heat exchanger being in a condenser mode removes the heat of the compressed refrigerant to atmosphere via a heat exchange with the ambient air which concurrently regenerates the desiccant material thereon. Accordingly, the performing apparatus enables the room return air to be continuously and simultaneously conditioned to the preselected parameters without the need of inefficient cooling and/or drying beyond the desired temperature or absolute humidity of the conditioned air. Thus, the utilization of the thermal energy in the process is highly efficient lending to an energy efficient air conditioning system.
It is therefore a general object of this invention to provide an improved, energy efficient air conditioning system utilizing a novel air thermodynamic cycle and performing apparatus which simultaneously cools and dries the room return air, and thus conditions said air to selected states of temperature and humidity.
Another object of this invention is to provide an air conditioning system, as aforesaid, which removes the sensible heat of the return air, i.e., temperature cooling, only to the extent required to reach the desired temperature of the conditioned air.
Another object of this invention is to provide an air conditioning system, as aforesaid, which removes the latent heat of the room return air, i.e., moisture removal, only to the extent required to reach the desired humidity of the conditioned air.
Still another object of this invention is to provide performing apparatus for the air conditioning system, as aforesaid, having first and second heat exchangers equipped with a desiccant material thereon for moisture removal/drying of the room air.
A further object of this invention is to provide performing apparatus, as aforesaid, which has control means therein for selectively routing the refrigerant and room and outside ambient air to the selected heat exchangers to allow the heat exchangers to operate in either condenser or evaporator modes relative to the refrigerant and room and ambient air passing therethrough.
A particular object of this invention is to provide performing apparatus, as aforesaid, wherein one heat exchanger is in the evaporator mode and removes the sensible heat from the room return air with its desiccant simultaneously removing the latent heat therefrom.
Another particular object of this invention is to provide a performing apparatus, as aforesaid, wherein the other heat exchanger is in the condenser mode and in heat exchange with a fluid such as the outside ambient air thereby providing for condensation of the refrigerant with a concurrent drying and regeneration of the desiccant material thereon.
Still another object of this invention is to provide a performing apparatus, as aforesaid, which efficiently uses the thermal energy produced therein and thus achieves a high coefficient of performance.
Other objects and advantages of this invention will become apparent from the following description taken in connection with the accompanying drawings, wherein is set forth by way of illustration and example, an embodiment of this invention.